Гибридная система «слоистый силикат магния – хлорин е6 13(1),15(2),17(3)-N,N',N''-(2-гидроксиэтил)триамид»

Abstract

Matrices based on layered silicates have a set of useful properties, in particular, they are able to increase the stability and photosensitizing ability of porphyrins. Hybrid systems “layered silicate - porphyrin (metal porphyrin)” are promising as active components of systems for light collecting and artificial photosynthesis, catalysts, photocatalysts. The hybrid systems with content of 1.4∙10-6 and 4.2∙10-6 mol of the chlorin e6 13(1),15(2),17(3)-N,N',N''-(2-hydroxyethyl)triamide per 1 g of layered magnesium silicate was obtained by heat treatment method of a synthetic layered magnesium silicate of hectorite composition when treated with an aqueous-alcoholic solution of organic component. The molar ratio of the starting components is: Mg(OH)2 : SiO2 : LiF = 1 : 1.51 : 0.25 : chlorin e6 derivative = 1 : 1.51 : 0.25 : (19.93∙10-5 – 59.58∙10-5). Using dynamic light scattering and laser Doppler electrophoresis, it was shown that the introduction of chlorin e6 13(1),15(2),17 (3)-N,N',N''- (2-hydroxyethyl) triamide leads to the growth of hybrid particles (162 ± 3 nm) and a decrease in their aggregative stability (-30 ± 1 mV), compared with the initial layered magnesium silicate (133 ± 1 nm, -33 ± 1 mV). In this case, the introduction of more hydrophilic chlorin e6 13(1),15(2),17(3)-N,N',N''-(2-hydroxyethyl)triamidе, in the molecule of which there are three fragments of ethanolamine, allows to obtain smaller hybrid particles (162 ± 3 nm), compared with hybrid particles (248 ± 6 nm) formed by the action of chlorin e6 13(1),17(3)-N,N'-(2-hydroxyethyl)diamide15(2)-methyl ether, in the molecule of which there are two fragments of ethanolamine. Using the methods of X-ray phase analysis and electron spectroscopy in the UV-visible region, it was found that individual molecules of chlorin e6 13(1),15(2),17(3)-N,N',N''-(2-hydroxyethyl)triamide were sorbed on the surface of silicate particles due to the electrostatic interaction between the protonated molecules of the macrocycle and the ionized hydroxyl groups of magnesium silicate. It was shown that the higher hydrophilicity of chlorin e6 13(1),15(2),17(3)-N,N',N''-(2-hydroxyethyl)triamide, compared with chlorin e6 13(1),17(3)-N,N'-(2-hydroxyethyl)diamide15(2)-methyl ether did not contribute to the intercalation of the organic component into the interlayer space of layered magnesium silicate under the conditions of a water-alcohol medium.